Blackmagic cameras can produce amazing results and there are countless examples on the Internet. As a Pocket Cinema Camera user, I am always amazed what this little camera can produce when it's set properly. In this post, I would like to share a few insights on how to get the best results out of the Blackmagic sensors. My experience is based on the Pocket camera, but from what I know all the information below apply to the other camera models as well.
Blackmagic cameras love light and they want to be overexposed.
I never expose the image for the final look. I always overexpose the picture and use the Zebras to watch the highlights – this technique is called Exposing To The Right (ETTR). Looking at the histogram we try to push the graph to the right side – hence the name.
When in Raw mode (90% of the time) I set the zebras to 100% and expose the picture to just touch the zebras in the highlights.
Have a look at the below picture from the set:
The window is clipping but in reality, when I lower the exposure by 1/3 EV it's fine, so I know that these highlights are recoverable. The highlights on the face are almost clipped – when I increase the exposure by 1/3 EV zebras start to appear.
When we have a look at this particular frame in Rec. 709 and BMDFilm color space it looks like this:
and the graded picture looks like this:
Clearly, all the highlights information is there. We can lower the exposure in post, giving it a dark mood, but the quality and sharpness are there. If I exposed it to the levels that can be seen in the graded version there would be a significant amount of noise in the shadows.
Here's another example:
The highlights on the left chick (camera right) are 1/3 EV from clipping. In the graded version, we can see that all the information is there.
When we zoom into 100% and 200% we can see how much details the camera was able to capture.
So what’s the best workflow to get the best results?
Here's what I do:
- Light the scene and monitor the contrast levels for the final exposure using False Color in the monitor.
This step is just to make sure that all the levels are consistent throughout the angles. The brightest area of the picture might change depending on the angle (window in the frame or not, for instance).
- Once the contrast ratios are there, overexpose the camera to the point where zebras start to appear on the screen.
- Repeat for all the angles in the scene.
In order to be able to do it quickly, have some ND's handy so that you can get the final look on the monitor (lower the exposure) when setting up the ratios. When you are done, just remove them until you hit the clipping point (increase the exposure).
ND fader might be a quick way to do it in some scenarios.
Understanding the Zebras
In case you wanted to read a bit more about Blackmagic cameras, zebras and exposing in general – some time ago I posted an article describing all that in depth:
If I wanted to compress the whole article to one sentence, it would be "always expose to the right".
Keep in mind that Blackmagic cameras are cinema cameras and they are not meant to be used as documentary tools. They certainly not low-light cameras and they produce the best results in controllable (well lit) environments.
Also published on Medium.